Steam-boiler



(No Model.)-

J. MITCHELL.

, STEAM BOILER.

Patented Dec. 30, 1884.

I WITNESSES l INVENTOR.

ATTORNEYS.

N. PETERS. Plmmuum m m-r. Washington. Ill.

; ATENT rricn.

JOHN BIITOHELL, OF LOUISVILLE, KENTUCKY.

STEAM-BOILER.

SPECIFICATION forming part of Letters Patent No. 310,071, dated December30, 1884.

Application filed September 19, 1883. Renewed Novemherlfl, 1884. (N0model.)

To all whom it may concern:

Be it known that I, JOHN MrrcirnLL, a citizen of the United States,residing at Louisville, in the county of Jefferson and State ofKentucky, have invented certain new and useful Improvements inSteam-Boilers; and I do hereby declare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

This invention consists in certain improvements in the construction ofsteam-boilers, as hereinafter described and claimed.

In the drawings, Figure 1 represents a longitudinal vertical section ofaboiler constructed according to my improvements. Fig. 2 represents asectional plan view thereof. Fig. 3 represents a section on the line 3 3of Fi 2. Fig. 4 represents a vertical section of the combastion-chamber.

My invention consists, essentially, in constructing locomotive and othersteam boilers with the combustion-chamber in the center of the waist ofthe boiler, and in extending a perforated pipe transversely across saidcombustion-chamber, said perforated pipe connecting at one end witheither the exhauststeam pipe from the engine or with a suitablelive-steam supply, whereby steam is supplied to the combustion-chamberfor the purpose of increasing the combustion of the smoke, cin- I ders,and gases therein.

A represents the walls of a boiler, of ordinary construction.

13 represents the fines or tubes, which, instead of extending the entirelength of the boiler, are of half the usual length.

0 represents the combustion chamber, which is arranged centrally ornearly centrally of the waist of the boiler, and with which the innerends of each series of flues connect. By thus arranging thecombustion-chamber centrally of the waist of the boiler, a much largerquantity of the smoke resulting from the combustion of the coal or othermaterial is consumed than where the combustion chamber is placed at therear end of the waist;

and by forming the dues of half-lengths, instead of extending themcontinuously throughout the length of said waist, their expansion andcontraction are considerably lessened or avoided, they are more easilyremoved from and placed in position, and a great saving is effected bytheir use, as it is well known that the tubes are more inj uriouslyaffected at those ends nearest the fire-box than at their extendin abouthalf around on the upper side. This pipe has a closed end, I), which,

when said pipe is passed through a hole in or about the center of oneside of the combustion-chamber, is secured to theinner face of theopposite end ,thereof by any suitable means. The opposite end, 0, ofsaid perforated pipe is screw-threaded, and is screwed into position andsupported therein within a screw-threaded flange, (l, on the outside ofthe waist of the boiler. This screw-threaded end is open, and hassuitable connection either with the exhaust-pipe of the engine, by meansof which the exhaust-steam therefrom is conveyed to such perforatedexhaust-pipe, or it is similarly connected with a live-steam supply, asdesired or found convenient. Steam, either exhaust or live, as desired,as it passes into this perforated tube E, escapes therefrom through theperforations a in the form of jets or spray into the combustionchamber,and as the smoke, cinders, and gases collect in said combustiolrchamberand co me in contact with the flame and the steam jets or spray, anincreased consumption of the products of combustion is secured over thatsecured by the ordinary form of boiler.

Having thus described myinvention, Iclaim i chamber, substantially asand for the purpose and desire to secure bv Letters Patent of the I setforth.

n [0 United States In testimony whereof I affix my signature in Atubular steam-boiler having a combuspresence of two witnesses. 5tion-chamber dividing the tubes transverse- JOHN MITCHELL.

Vitn esses: I

WM. RUSSELL, W. W. MELONE.

1y between the fire-box and uptake, in 00111- bination with a perforatedpipe through which steam is admitted to said combustion-

